When the director and producer JJ Abrams gets cryptic, there is usually something large and monstrous lurking in the dark. The teaser trailer for 2011's Super 8 gave us scary extraterrestrial rumblings from a sealed container on a derailed train, while 2008's Cloverfield promised an imminent New York yuppie apocalypse courtesy of a giant lizard. Now comes the latest enigma from Abrams's Bad Robot production company.

The brooding video segment, titled Stranger, arrives unheralded – creating much confusion in the blogosphere. Is it a new movie, TV show, or something else? Some have guessed that it is a teaser for Abrams's upcoming collaboration with Alfonso Cuarón on the NBC show Believe, reportedly about a girl with supernatural abilities who is protected from evil forces by a death-row convict who breaks out of jail.Others reckon that the clip could be a sneak peak at a novel Abrams is co-writing with Doug Dorst, currently titled S, and promising to be a "multilayered literary puzzle of love and adventure". It is certainly not Star Wars: Episode VII – unless Abrams is taking the space saga in an offbeat direction.

That's that sewn up ... one of the mysterious figures at the centre of JJ Abrams' Stranger teaser trailer. Photograph: Bad Robot Productions/YouTube

With a noirish feel that recalls everything from Great Expectations to old Guinness adverts, the teaser throws a lank-haired man from the moonlit waves. "He arrived knowing nothing of himself. Who is he? Soon he will know," intones a narrator. "Because what begins at the water shall end there – and what ends there once more begin." The man pulls what appears to be rope from his wrists and stares back suddenly at a sinister light in the distance. Slowly, the lilting piano score shifts into uneasy dissonance, and it becomes clear that the light is being held by a second, following figure, a threatening presence whose lips are sewn shut.

A new type of monster then? Or is Abrams employing smoke and mirrors to conceal what's really going on? Fingers crossed that scary mute man is not the new Jar Jar Binks. But who is he?